Synthesis of nanocrystalline TiO2 thin films by liquid phase deposition technique and its application for photocatalytic degradation studies

A transparent, high purity titanium dioxide thin film composed of densely packed nanometer sized grains has been successfully deposited on a glass substrate at 30°C from an aqueous solution of TiO2-HF with the addition of boric acid as a scavenger by liquid phase deposition technique. From X-ray diffraction measurement, the deposited film was found to be amorphous and turns crystalline at 500°C. The deposited film showed excellent adherence to the substrate and was characterized by homogeneous flat surface. TiO2 thin films can be used as a photocatalyst to clean up organohalides, a class of compound in pesticides that pollute the ground water. Photocatalytic degradation experiments show that indanthrene golden orange dye undergoes degradation efficiently in presence of TiO2 thin films by exposing its aqueous solution to ultraviolet light. The suitable surface structure and porosity increases the photocatalytic activity. It was also observed that hemin doped TiO2 thin films break up organohalides at a surprisingly high rate under visible light

Effects of Ni doping on photocatalytic activity of TiO(2) thin films prepared by liquid phase deposition technique

The TiO(2) thin films doped by Ni uniformly and non-uniformly were prepared on glass substrate from an aqueous solution of ammonium hexa-fluoro titanate and NiF(2) by liquid phase deposition technique. The addition of boric acid as an F(-) scavenger will shift the equilibrium to one side and thereby deposition of the film is progressed. The rate of the reaction and the nature of deposition depend on growing time and temperature. The resultant films were characterized by XRD, EDAX, UV and SEM. The result shows that the deposited films have amorphous background, which becomes crystalline at 500 degrees C. The EDAX data confirms the existence of Ni atoms in TiO(2) matrix. XRD analysis reveals the peaks corresponding to Ni but no peak of crystalline NiO was found. The transmittance spectra of Ni uniformly and non-uniformly doped TiO(2) thin films show 'blue shift and red shift', respectively. Ni-doped TiO(2) thin films can be used as photocatalyst for the photodegradation of methyl orange dye. It was found that, organic dye undergoes degradation efficiently in presence of non-uniformly Ni-doped TiO(2) thin films when compared to uniformly doped films and pure TiO(2) films under visible light. The photocatalytic activity increases with increase in the concentration of Ni in case of nonuniformly doped thin films but decreases with the concentration when uniformly doped thin films were used

Characterization and photocatalytic activity of boron-doped TiO(2) thin films prepared by liquid phase deposition technique

Boron doped TiO(2) thin films have been successfully deposited on glass substrate and silicon wafer at 30 degrees C from an aqueous solution of ammonium hexa-fluoro titanate and boron trifluoride by liquid phase deposition technique. The boric acid was used as an F(-) scavenger. The resultant films were characterized by XRD, EDAX, UV and microstructures by SEM. The result shows the deposited film to be amorphous which becomes crystalline between 400 and 500 degrees C. The EDAX and XRD data confirm the existence of boron atom in TiO(2) matrix and a small peak corresponding to rutile phase was also found. Boron doped TiO(2) thin films can be used as photocatalyst for the photodegradation of chlorobenzene which is a great environmental hazard. It was found that chlorobenzene undergoes degradation efficiently in presence of boron doped TiO(2) thin films by exposing its aqueous solution to visible light. The photocatalytic activity increases with increase in the concentration of boron

Abdominal Tuberculosis in Surgical Practice in Northern Nigeria

Background: Abdominal tuberculosis is a common complication of pulmonary tuberculosis. With the rising incidence of HIV, tuberculosis has become a major public health problem particularly in developing countries. Methods: This is a retrospective study involving patients whose surgical specimens were processed at the central histopathology laboratory of the Ahmadu Bello University Teaching Hospital (ABUTH) Zaria - Nigeria, between January1975 to December 2006.Results: There were 68 males and 49 females, aged 12-70 years (mean 28.6yrs 11yrs). While paroxysmal dry cough was present in about 20 patients, abdominal pain and distension were very common. Concomitant pulmonary tuberculosis was confirmed in 15 patients (14%). The findings at Surgery in 66 patients are presented in fig.2. Multiple deposits on the peritoneum and omentum were the commonest findings (48.7% and 26.2%) respectively. Conclusion: Abdominal tuberculosis is not uncommon and there is need to establish an early less invasive diagnostic protocol.Keywords: Abdominal Tuberculosis, Nigeria

Isolation and identification of E-coli 0157:H7 amongst Sudanese patients with bloody diarrhea and in animals

E.coli 0157:H7 is present as a commensal in the intestine of animals and as a pathogen in human beings. It causes bloody diarrhoea due to the secretion of a verotoxin which may lead to lethal complications.Objective: This study is aimed at determining the presence of this organism in animals and patients. Methods: Rectal swabs were collected from 250 cows. Stool specimens were obtained from 200patients presenting with macroscopically or microscopically bloody diarrhoea. All specimens were cultured on sorbitol MacConkey agar and incubated at 37°C overnight. Non-sorbitol fermenting colonies were identified by different biochemical and serological tests as E.coli 0157:H7. Antibiotic sensitivity was done for the isolates using ampicillin, cephalexin, ciprofloxacin, co-trimoxazole, gentamicin, and tetracycline. Results: Patients (n = 10, 5%) with bloody diarrhoea were found to harbour E.coli 0157:H7 in their stools. All isolates (in humans) were resistant to ampicillin. Eight (80%) were resistant to tetracycline and cephalexin, six (60%) to co-trimoxazole, and four (40%) to gentamicin. All isolates were sensitive to ciprofloxacin. Sixty percent of the human isolates were resistant to three antibiotics and 40% to four antibiotics. Twenty of the cows (8%) were found to be carriers of E.coli0157:H7. All isolates (in animals) were resistant to ampicillin, five (25%) to tetracycline and cephalexin and four (20%) to co-trimoxazole. All animal isolates were sensitive to gentamicin and ciprofloxacin. Thirty five percent of the animal isolates were resistant to two antibiotics and 25% to three antibiotics. Conclusion: The isolation of E.coli 0157:H7 from animals and patients should direct the attentionof physicians and paediatricians to consider the possibility of infection and complications by this organism.Key words: Antibiotic sensitivity, sorbitol MacConkey agar, serological tests

Pro-asylum Advocacy in the EU: Challenging the State of Exception

Introduction. This chapter explores examples of how pro-asylum advocates challenge the harsh measures used to punish those who try to enter or reside in the EU illegally, taking examples from The Netherlands and the UK. We explore organized resistance to the ‘3-Ds’, which are so typical of EU-wide migration policies: destitution, detention and deportation. Together these are the backbone of policies of deterrence. Sections 2 and 3 explore how ‘global apartheid’ and the ‘state of exception’ within the EU connect. Giorgio Agamben (2005) first theorized the “state of exception” and Kohler, “global apartheid” (1978). The state of exception is the regional context for pro-asylum advocacy work, and global apartheid is the global context within which the EU-wide state of exception can be understood (Webber 2000; Migreurop 2009). In section 4, the ‘shared injustice frames’, or common worldviews, of pro-asylum advocacy networks in the EU, are briefly explored. Section 5 presents examples of pro-asylum advocacy work from the UK and the Netherlands. These examples draw on our own background experience and research. We explore how two pro-asylum advocacy organizations, one a loose network, the other a small NGO, have tried to organize to protect those seeking sanctuary against the 3-Ds. The right not to be deliberately made homeless, not to be imprisoned at will, and not to be forcibly expelled to dangerous countries, are thus the main focus of these organizations, and of section 5. In section 6, we briefly explore some positive recent developments, such as the ‘sanctuary campaign’ in the UK, but also how resistance to deterrence policies has had to go ‘underground’ in the face of criminalization in both the EU and elsewhere, such as Canada (Fekete 2009; Nyers 2003)

Seroprevalence of hepatitis C virus antibodies amongst blood donors in Ahmadu Bello University Teaching Hospital (ABUTH) Kaduna

Background: Hepatitis C virus (HCV) is one of the most common transfusion transmissible infections hence the introduction of routine screening for its antibodies in blood donors in most blood banks. Methods: This was a retrospective study in which the blood donor screening register for all intending donors were reviewed and analyzed. Results: There were 4,731 potential donors with age range 20-41years. Eighty six (1.8%) were sero-positive to HCV antibodies with a decreasing incidence over the period under review. The highest incidence was recorded the age group 31-40 years. Aim: To determine the sero-prevalence of HCV among blood donors in ABUTH Kaduna. Conclusion: HCV infection is not uncommon in our environment hence the need to emphasize it’s routine screening among all potential donors.

Acute oral toxicity of two products from a microbial pest control agent (Beauveria bassiana) on physiological status aspects of male albino rats

Background: Synthetic pesticides have accumulated in environment causing harm to humans and ecosystems. As a result, the use of biopesticides in agriculture and public health has expanded as a substitute for traditional pesticides. Purpose: To investigate the acute oral toxicity of Beauveria bassiana, on physiological status aspects of male rats. Material and Methods: Metabolic crude (MC), and wettable powder formulation (2.5% WP) from the local isolate of B. bassiana (AUMC 9896) were tested on adult Sprague Dawley (SD) male rats by single oral dose. Results: There was no evidence of death or toxic symptoms in any of the treated groups. In contrast, each product caused a significant increase in the body weight gain and relative liver weights of B. bassiana-exposed male and reduced the brain somatic index with WP only as compared to the control. The studied bioinsecticide also caused a substantial rise in total erythrocyte and absolute differential leucocyte counts, while red blood cell distribution width (RDW) and platelet count (Plt) were decreased significantly. Furthermore, male rats exposed to both types of B. bassiana, aspartate aminotransferases (AST), total protein (TP), albumin (Alb), AST/ALT, triglyceride, and very low-density lipoprotein cholesterol (VLDL) were elevated compared to the untreated group, whereas alkaline phosphatase (ALP) activity, globulin (Glb), Alb/Glb, urea content, and low-density lipoprotein cholesterol (LDL) count fluctuated between increased and decreased. Also, B. bassiana-treated rats had lower serum cholesterol and high-density lipoprotein cholesterol levels (HDL) values.Conclusion: These results suggest that both treatments have slight effects on complete blood count (CBC) of treated male rats and marked effect on liver function, lipid profile, body weight gain and somatic index of the liver and brain

Efficient synthesis of novel bis(dihydropyrano[2,3c]pyrazoles), bis(4H-chromenes) and bis(dihydropyrano[3,2-c]chromenes) with amide functionality

A synthesis of novel bis(1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles), bis(4H-chromene-3-carbonitriles) and bis(dihydropyrano[3,2-c]chromenes), which are linked to aliphatic spacers via amide linkages was achieved via multicomponent reactions (MCR) of the appropriate bis-aldehyde with two equivalents of both of malononitrile and 3-methylpyrazol-5-one, dimedone or 4-hydroxycoumarin in a basic solution